The Rainier event

On Sept. 19, 1957, the University of California Radiation Laboratory, Livermore detonated the first contained underground nuclear explosion, “Rainier,” into a long tunnel beneath a high mesa in the northwest corner of the Nevada Test Site. The Rainier shot was a success, confirming the feasibility and safety of underground testing. So too, the results suggested the possibility of several applications of nuclear detonations not related to weapons development.

The idea of using nuclear explosions for non-military purposes was first raised by President Dwight D. Eisenhower in his famous “Atoms for Peace” speech in December 1953 — an idea that resonated with Edward Teller. In early 1956, Teller and geophysicist Dave Griggs proposed that serious considerations should be given to the possibility and economic feasibility of testing nuclear weapons underground. They noted that successful underground testing could lead to many practical operational benefits, such as the removal of weather as a factor in testing, as well as environmental advantages, including eliminating fallout and other offsite effects — important considerations given the growing concerns over atmospheric testing.

The study of the general concept and viability of the underground testing technique was undertaken by the Livermore Test Division in the spring of 1956. That summer, Harold Brown (Livermore director, 1960-1961) proposed a symposium on the uses of nuclear explosions for non-military purposes to the Atomic Energy Commission (AEC), and a meeting was held at Livermore in February 1957. Some 24 papers were presented, covering a broad array of ideas. While interest was high, discussions were hampered by the lack of data on the effects of underground explosions. In April 1957, the AEC gave the go-ahead for the Rainier test; and, shortly thereafter, in June 1957, the commission established the Plowshare Program to explore peaceful nuclear uses. Rainier, however, was not officially a Plowshare test, although its results gave a boost to the program. Gnome, which was detonated in December 1961, after the Soviets broke the nuclear test moratorium, was the first Plowshare test.

Rainier was fired in September 1957, producing around 200,000 tons of broken rock and 500,000 tons of crushed rock. The test had been announced in advance so that seismic stations throughout the United States and Canada could attempt to record a signal. The seismic effects, though readily measurable, were negligible. Geological samples were gathered for radiochemistry analysis by drilling a series of holes through the above mesa and in the original tunnel. Additional data was collected by mining a tunnel into the bottom of the explosion cavity about 15 months after the event, after radioactivity had decayed to manageable levels.

In all, the data gathered from the test gave a tremendous boost in confidence that a variety of engineering applications of contained explosions were possible and could be safely implemented. Among the ideas discussed at the Atoms for Peace Conference, held in Geneva in the fall of 1958, were earth moving, shattering and retorting of oil shale in situ, recovery of geothermal heat, power generation and isotope recovery — ideas that would be put to the test in Plowshare Program operations.

In addition, the information generated by Rainier provided a basis for subsequent decisions made in 1963 to enter into the Limited Test Ban Treaty, which banned atmospheric nuclear weapons tests and established systems, including an international array of seismic detectors, to monitor nuclear test activities worldwide.